Network-centric tactical environments rely heavily on the timely dissemination of critical information related to sensors, situational awareness, command, and control to soldiers, planners, and other receivers in order to execute a successful mission. Typically, these environments use a communications network including hundreds of platforms, sensors, decision nodes, and computers communicating with each other to exchange information to support collaborative decision making in a real-time, dynamically changing, and critical situation.
The communications network used in these environments often disseminate information using publish-subscribe (“pub-sub”) communication paradigm with Internet Protocol (“IP”) multicast services as the transport mechanism. In pub-sub, the sender or publisher sends messages without knowing the existence or identity of the receivers or subscribers. These messages are received only by those that have subscribed to the information contained in the messages. A subscriber can receive information related to a particular content regardless of the identity of the publisher. This paradigm is beneficial in environments where the communicating parties are frequently changing, such as in a tactical network.
IP multicasting is a networking technology that sends information as a packet to a group of destinations simultaneously over a link once. The nodes in the network replicate the packet to reach the multiple destinations as needed when downstream receivers are reached over multiple links. A multicast group is a set of receiver nodes that elect to receive information or packets sent to the group. A multicast address is used by a source node to send packets to each of the receiver nodes associated with the multicast group and by the receiver nodes to receive the packets.
It is often the case in network-centric tactical environments, that the number of multicast addresses and groups that can be used for pub-sub communications is limited. In such cases, it is necessary to disseminate information in an efficient manner.